JP5563736B2 - Multi-stage gear type processing machine - Google Patents

Description

The present invention relates to an apparatus for compressing a substance together with carbon dioxide gas, for example, as a fluid in a critical state, that is, processing such as kneading, decomposition, extraction or chemical synthesis under supercritical or subcritical carbon dioxide gas.

Numerous substance mixing, substance extraction, substance decomposition and chemical synthesis using supercritical carbon dioxide have already been proposed, and in particular in the field of extraction.

For example, in Patent Document 1, carbon dioxide is used as a working medium in a continuous processing method in which liquid food or liquid chemical is subjected to enzyme deactivation, sterilization, deodorization, extraction processing, or the like using a supercritical fluid or subcritical fluid. A compression process in which a liquid raw material is injected into a compressor suction process or a compression process and compressed together with carbon dioxide, and carbon dioxide and the liquid raw material are brought into direct contact to form a critical high-pressure gas-liquid mixed fluid. A liquid-gas separation process that separates high-pressure carbon dioxide gas and high-pressure carbon dioxide gas in which a liquid substance is dissolved from a high-pressure gas-liquid mixed fluid; It has been proposed to use a decompression process for discharging low-temperature carbon dioxide gas upon release, enzyme deactivation treatment, pasteurization treatment, and flavor extraction treatment.

In this proposal, since the raw material liquid is supplied to the compressor by a pump and the supercritical condition is achieved by the separator, a large number of devices are required, and the capital investment is excessive, which is not economically preferable. In addition, the operating conditions are limited to low temperatures, and there is a drawback that the application range is narrowed.

In Patent Document 2, the recovered polyester product is broken into flakes, washed, and dehydrated and dried in a screw kneading and extruding machine for the previous process, and a reforming agent and a catalyst are added to cause a reforming reaction. Furthermore, a recycled polyester product recycling method and apparatus in which foam extrusion is performed while adding a supercritical fluid by a post-process screw extruder has been proposed.

In this proposal, a screw extruder is used, but a reforming reaction is performed in the previous process and a supercritical carbon dioxide gas is injected in the subsequent process to produce a foamed product. There is no reaction inside. Moreover, since it is a screw type, gas leakage occurs and processing cannot be performed in a state where gas is contained in a low-viscosity substance.

Patent Document 3 proposes an extruder that connects at least two gear pumps and melts and mixes unmelted vinyl chloride powder in the gear pump.

In this proposal, it is considered preferable to connect two or more gear pumps in view of the kneading effect, but a control method in the case where the rotation speed between the gear pumps is different is not described. When gear pumps of the same capacity are connected at the same speed, abnormal pressure does not occur between the connected gear pumps, and operation is possible. However, when gear pumps with different capacities are connected, for example, when a small capacity gear pump is connected next to a large capacity gear pump, an abnormally high pressure is generated between the gear pumps, and an excessive load is applied to the large capacity gear pump. You can't actually drive.
JP 2002-204942 A JP 2000-264998 A JP 11-34045 A

An object of the present invention is to provide an apparatus capable of performing processing such as decomposition, mixing, or extraction of a substance with good operability using supercritical or subcritical gas.

In the present invention, the above-mentioned problem has been solved by installing a multi-stage gear unit having a method for controlling the pressure of gas compression of a substance in which gas is mixed, or for controlling a part of the transferred substance in reverse flow.

That is, the apparatus of the present invention is a processing apparatus for continuously kneading a gas-mixed substance, and has two or more gear-type transfer sections having different gear dimensions (that is, different transfer section capacities). It is characterized in that the pressure difference of gas compression is controlled by the transfer capacity difference between two successive gear-type transfer sections, or a part of the transfer material is made to flow backward to make the actual transfer capacity constant.

Hereinafter, the sum of the volume of the substance and gas at the temperature and pressure when the gas-mixed substance passes through the gear-type transfer unit within a certain time is referred to as “transfer capacity”, and the transfer capacity capacity of the gear-type transfer unit is expressed as “ “Transport capacity”. The above-mentioned transfer capacity is referred to as “substantial transfer capacity” as the sum of the volume of the substance and gas at the same temperature and pressure equivalent to 1 atm.

The continuous two-stage gear-type transfer unit is provided with a plurality, preferably 2 to 4, of gears paired between them, and the transfer capacity transferred by each gear-type transfer unit is Depending on the number of rotations and dimensions (module, pitch circle diameter, gear thickness, etc.) of the gear type transfer unit. The capacity of the transfer section is approximately proportional to the product of the number of rotations of the gear, module, pitch circle diameter, and gear thickness, but is it actually determined by the method of compressing and adjusting the gas so that the actual transfer capacity is constant? It is preferable to apply a method of adjusting a part of the flow back from the outlet side to the inlet side. Such a gear-type transfer unit is preferably provided, for example, following the extrusion screw, and since the first gear transfer unit capacity of the gear transfer unit is smaller than the second gear transfer unit capacity, It becomes possible to make the pressure negative. By providing a gear having a smaller transfer section capacity than the second gear behind the second gear, the pressure can be increased or a desired effect can be obtained.

In the apparatus of the present invention, a low-viscosity raw material can be continuously processed, and a high-pressure condition of supercritical or subcritical gas can be generated by the gear-type transfer unit.

The apparatus of the present invention is an extruder or an injection molding machine, and at the same time, general-purpose chemistry capable of continuously performing decomposition, mixing or extraction of substances under supercritical or subcritical carbon dioxide gas under a wide range of operating conditions. The equipment is inexpensive and the equipment is inexpensive because the process is not diverse. In addition, the gear-type transfer units can be stacked vertically, and the installation area can be reduced with a compact device.

It is explanatory drawing of the gear pump structure of a pressure | voltage fall part. It is explanatory drawing of the gear pump structure of a pressure | voltage rise part. It is explanatory drawing of the gear pump structure of a kneading part. It is explanatory drawing which shows the structure of an orifice part. It is explanatory drawing which shows the structure of a pressure control part. The structure of a multistage gear type extruder is shown, (I) shows the front part and (II) shows the rear part. 1 shows the structure of a multi-stage gear type foam injection molding / extruder. The structure which arranged the multistage gear type extruder horizontally is shown, (1) is a plane sectional view, (2) is a longitudinal section. FIG. 2 is a plan sectional view of a structure in which multi-stage gear extruders are arranged in an arc shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Shaft 3 Shaft 4 Shaft 5 Screw 6 Gear 7 Conduction relay gear 8 Hopper 9 Orifice 10 Vent hole 11 Die 12 Nozzle 13 Flow path 14 Return path 15 Arrow 16 Servo motor 17 Servo amplifier 18 Pressure electric signal 19 Resin pressure gauge 20 Pressure gauge 21 Pressure reducing valve 22 Check valve 23 Melting section 24 Pressurizing section 25 Supercritical section 26 Orifice section 27 No-flight section 28 Pressure adjusting section 29 Gas injection section 30 Boosting section 31 Supercritical section 32 Decreasing section

The present invention will be described with reference to an example shown in the drawings.
The apparatus of the present invention uses a multi-stage gear-type transfer unit combining gears as shown in FIGS. 1, 2 and 3, and processes a substance mixed with gas transferred between them as a fluid in a critical state. It is. For example, the biaxial horizontal gear extruder of FIG. 6 includes a multi-stage gear type transfer unit following the biaxial extrusion screw of the raw material supply unit, and is provided inside the cylinder 1 that is superheated by an electric heater. An A-axis screw and a B-axis screw are provided, the resin raw material supplied from the hopper 8 is melted while being transferred, and the molten resin in the section of the melt section 23 flows into the next gear as shown in FIG. . The gear T1 and the subsequent gear T2 have a relationship of T1 <T2. In the gear of FIG. 1, the pressure-lowering portion X is configured, and the gas is compressed by the supply pressure set by the pressure-reducing valve 21 and the gear thickness is reduced. A certain amount of gas of volume transfer amount corresponding to the dimensional difference (T2-T1) is injected. The fluid after the gear T2 is a mixture of gas and resin. Therefore, the gas injection amount is larger as the supply pressure set by the pressure reducing valve 21 is higher. This gas is deaerated in the vent hole 10 sucked by a vacuum pump. In this example, the screw is biaxial, but may be uniaxial.

FIG. 1 shows a gear pump structure of the step-down portion X, and (1) in FIG. 1 shows a plan view. (2) in FIG. 1 is a cross-sectional view seen from the Out side axial direction, and (3) and (4) in FIG. 1 are side views. As shown in the figure, an A-axis shaft 2 and a B-axis shaft 3 pass through the inside of the cylinder 1, and mesh with each other, and gears T1 and T2 having different thicknesses are fixed, and two sets of gear pumps Is configured. The A-axis and B-axis shafts 2 and 3 are driven in a rotational direction as indicated by an arrow 15, and the resin filled in the flow passage 13 is conveyed from the In side to the Out side illustrated by a gear. Under the condition that the thicknesses of the gears T1 and T2 are T1 <T2, it affects the tendency to increase the transfer capacity of the gear T2 rather than the transfer capacity of the gear T1.

Next, the case where the substance is a melt of a thermoplastic resin and the gas is carbon dioxide will be described as an example. In FIG. 1, when a fluid in which resin and gas are mixed flows from In, the transfer capacity of the gear T1 corresponds to the sum of the resin volume and the volume in which the gas is compressed by the pressure P1. The transfer capacity of the gear T2 corresponds to the sum of the resin volume that has passed through the gear T1 and the volume in which the gas is compressed by the pressure P2. Under the condition that the gear thickness is T1 <T2, the transfer capacity is larger by the gear T2 than the gear T1, and the pressure is P1> P2. The structure of (3) in FIG. 1 is used for the first stage of the multi-stage gear group mainly for the purpose of gas injection. When fluid containing only resin that does not contain gas flows from In, the gas volume compressed to carbon dioxide pressure P2 supplied from the Gas inlet regardless of P1 corresponds to the difference in gear thickness dimension (T2-T1). Become volume. In this case, it is not necessary for the fluid flowing from In to be a resin alone, and even if it is a mixture of resin and gas, carbon dioxide gas can be injected under the balanced conditions of the gears T1, T2, P1, and P2. The structure of (4) in FIG. 1 is used at the end of the multi-stage gear group mainly for the purpose of reducing the pressure of the fluid mixed with gas from the supercritical region to the subcritical region.

2 shows the gear pump structure of the booster Y. FIG. 2 (1) is a plan view, FIG. 2 (2) is a cross-sectional view seen from the axial direction on the Out side, and FIG. 2 (3) is a side view. Indicates. The fluid flowing from In is, for example, a sufficiently compressible fluid in which resin and gas are mixed. Even if the gear thicknesses are T1> T2> T3, the actual transfer capacity is the same for each gear. Therefore, the internal pressure in the flow passage 13 is increased to P1 <P2, and the pressures of P1 and P2 respectively. Since the fluid is compressed, the transfer capacity is balanced. If it is assumed that the actual transfer capacity is unknown and the pressure P0 of the fluid flowing from In is extremely high, P0 <P1 is not always satisfied under the condition of T1> T2, and W cannot be defined as a boosting unit. Usually, at the stage of designing, since the actual transfer capacity and P0 are known as design values, the boosting unit can be configured even by combining two stages of gears. For the reasons described above, FIG. 2 is composed of a combination of three gears. The structure shown in FIG. 2 is mainly used for the following two applications.

As an example of application of the structure of FIG. 2, it is installed for the purpose of raising the pressure to the supercritical region in the next stage in which carbon dioxide gas is injected in the structure of (3) of FIG. In this case, the first stage of the boosting unit may be considered as the gear T2 in FIG.

An example of the application of the structure of FIG. 2 is a formulation for fully pregelatinizing starch (eg, a mixture of 58% starch and 42% water by weight). When the water is carbonated water in which carbon dioxide gas is previously dissolved in water, for example, in the apparatus of FIG. 6, when this mixture is supplied from the hopper 8, the screw 5 under the hopper sufficiently ingests the starch in the dilatant flow 2. The water turns into steam during the overheating transport to the first stage of the multi-stage gear using the shaft paddle screw. Since carbon dioxide is already contained in carbonated water, gas injection is unnecessary, and the structure shown in FIG. 2 is used for the purpose of increasing the pressure from the first stage of the multi-stage gear to the supercritical region.

FIG. 3 shows a gear pump structure of the kneading part Z, and FIG. 3 (1) shows a plan view. 3 (2) is a cross-sectional view seen from the Out-side axial direction, and FIG. 3 (3) is a side view. Further, (4) of FIG. 3 illustrates the movement relationship between the gears attached to the shafts 2, 3, and 4 of the A axis, the B axis, and the C axis and the fluid. As shown in FIG. 3 (2), the flow path is shown on the outer periphery of the A-axis gear. A part of the fluid passes from the Out side through the outer periphery of the A-axis gear and is supplied to the inlet of the C-axis gear. From the exit of the gear, the outer periphery of the A-axis gear returns to the In side through the return passage 14. The amount of this reverse flow is shown as FB in (4) of FIG. The kneading effect is excellent depending on the amount of FB, and the pressure on the In side and Out side is stabilized. In addition, as shown in FIG. 3 (5), a gear having the same function as that of the C-axis gear may be provided on the D-axis to use four gears. The amount of reverse flow with the C-axis gear is indicated as FBC, and the amount of reverse flow with the D-axis gear is indicated as FBD. This pair of gear portions can be used for both the pressure raising portion, the pressure reducing portion, and the portion where the pressure is balanced. The kneading and dispersing effect is extremely excellent.

FIG. 4 shows the orifice structure. Installed mainly in the supercritical section, the fluid flows in from In, passes through the narrow groove of the orifice 9, and exits from the flow path to Out. The fluidity of the fluid in the section where the gas is in the supercritical state is high, and the kneading and dispersing effect is further enhanced by providing an orifice in this section.

FIG. 5 shows the structure of the pressure control unit. Although the pressure control unit is mainly useful for multistage gear type machining devices for research and development, the pressure-lowering unit X using gears fixed to the A-axis and B-axis shown in FIG. Do not need. The purpose of providing a pressure control unit is mainly to investigate the relationship between the amount of carbon dioxide added and the pressure, etc., on the degree of chemical reaction and the degree of kneading dispersion, or to determine the specifications of the production machine. It becomes. A fluid passage is blocked in a non-flight section 27 without a screw groove at the rear stage of the orifice portion of the supercritical section of the screw, a bypass passage of a flow passage 13 is provided, and a gear 6 driven separately from the screw 5 by a servo motor 16 is provided. Via, it flows into the rear stage of the no-flight section 27. Normally, the gear 6 constitutes the step-down portion X with a two-stage gear. If the rotation speed of the servo motor is lowered, the pressure at the mounting portion of the resin pressure gauge 19 increases, and if the rotation speed of the servo motor is increased, the pressure at the mounting portion of the resin pressure gauge 19 decreases. The servo motor 16 is driven by a servo amplifier 17, and a pressure electric signal 18 is fed back from a resin pressure gauge 19 in response to a pressure command commanded to the servo amplifier, so that the servo motor 16 approaches the pressure set value. The number of revolutions is controlled to configure automatic pressure control.

FIG. 6 shows an example of a multi-stage gear extruder. Resin is supplied from the hopper 8 and heated by a heater, and the resin is heated and melted by the A-axis and B-axis biaxial screws 5 provided in the cylinder 1 to form a fluidized resin as shown in FIG. Reach the first stage. Although this example is configured with two axes, the purpose can be sufficiently achieved even with one axis. Carbon dioxide gas from the carbon dioxide cylinder is decompressed by the decompression valve 21 and supplied through the check valve 22 to the rear of the first stage of the multi-stage gear. The pressure of the supplied carbon dioxide gas is confirmed by a pressure gauge 20. The carbon dioxide gas is pressurized and kneaded by the screw installed in the supercritical section 25 through the pressurizing section 24 together with the resin carried by the screw 5, so that the carbon dioxide gas enters a supercritical state, and the next stage. The orifice section 26 is reached. The mixture of the resin and gas that has passed through the orifice section 26 is blocked in the next non-flight section 27 and flows into the pressure adjustment section 28 by the servo motor. The fluid that has passed through the pressure adjustment section flows into the screw portion in which the vent hole 10 is installed. At this time, the carbon dioxide gas is reduced in pressure from the supercritical state to the subcritical state. The mixed fluid of resin and gas is sucked and degassed through a vent hole to which a vacuum pump is connected. The latter stage from the vent hole reaches the die 11 with the same structure as a general extruder, and the fluid (resin) is cooled in a strand water tank and cut with a strand cutter, or cut with a hot cutter or an underwater cutter, etc. Is done. In some cases, the liquid can be taken out. Although the first to third gears are illustrated in the pressurizing section 24, the first and second gears are the step-down portions X described in FIG. 1, and the second and third gears. The gear is different in figure from the booster Y described in FIG. 2, but the transfer unit capacity of the three gears (described in the kneading part Z in FIG. 3) forming the third pair and constituting the backflow part is The gas volume is smaller than the second transfer section capacity, and the gas is further compressed to constitute the pressure increasing section Y.

FIG. 7 shows an example of a multi-stage gear type foam injection molding machine / extruder. The resin raw material is supplied from the hopper 8 and melted while passing through the screw 5 installed in the cylinder 1 heated by the heater. The purpose of the screw is to melt either uniaxially or biaxially, and either screw may be adopted. The melted resin reaches the gas injection section 29 (step-down part X as shown in FIG. 1) arranged at the first stage of the multi-stage gear part. In this section, gas is mixed into the resin and transferred to the pressure increasing section 30 disposed in the next stage. In this example, a method of combining three gears as shown in (1) of FIG. 3 is employed so that pressurization and kneading are simultaneously performed. The fluid is then transferred to the supercritical section 31 and the gas mixture enters the resin details. It is convenient to monitor the supercritical pressure by attaching a resin pressure gauge 19 to this portion. Next, the resin mixed with the gas passes through the pressure reducing section 32 and is injected into the mold of the injection molding machine through the nozzle 12 at the tip. The nozzle has a well-known mechanical nozzle structure that can discharge from the nozzle when pressed against the mold.
It is also possible to attach a round die or a T die instead of the nozzle and perform continuous foaming. The illustration is an example of the apparatus of the present invention, and the number of gear stages is not necessarily limited to the illustrated number of stages.

FIG. 8 shows an example of a multi-stage gear type extruder in which multi-stage gears are arranged horizontally. 8A is a plan view, and FIG. 8B is a side view. The gear thickness is T1 <T2> T3> T4. However, the gear thickness can be appropriately selected and arranged according to the purpose of use. Similarly, FIG. 9 shows an example of a multi-stage gear extruder in which multi-stage gears are arranged in an arc. The difficulty in arranging the multi-stage gears in a horizontal arrangement or an arc arrangement is the seal of the gear shaft, and the seal is more likely to break as the pressure increases. In the present invention, this problem is solved by providing the conductive relay gear 7. By providing conductive relay gears in a horizontal arrangement or circular arc arrangement, the complexity of the seal has been eliminated, and it has become compact, making it ideal for various supercritical compounds, supercritical extraction and supercritical reaction tester applications for laboratories. .

In order to obtain a substance in which gas is mixed, for example, in the apparatus of FIG. 6, gas is supplied through the check valve 21 through the check valve. However, the gas mixed into the resin or the like is not necessarily gas when injected. There is no need to be. It may be liquid when injecting. For example, even if water is added to the resin or starch from the hopper 8 and water vapor is generated during the transfer by the screw to form a fluid in which gas is mixed, a liquid is added from the gas inlet, and the multi-stage gear group In other words, the gas may be mixed with the gas by the internal heat. That is, in the present invention, a state where a gas component is mixed in a fluid passing through the multi-stage gear group is treated as a substance containing gas or a gas-containing substance.

A die is generally used for the outlet of the apparatus of the present invention. The die hole and the shape of the die are appropriately selected according to the following steps. For example, if the next step is film or sheet production, the shape of the die hole can be made into a slit shape, and production of the film or sheet can be made continuously. Also, if the next step is discontinuous, the processed material is taken out in the form of a cord and cut with a cutter to produce a pellet, extruded into a sheet to produce a square pellet, or round with a hot cutter or underwater cutter. Pellet can also be manufactured. In some cases, it can be taken out in liquid form.

In some cases, the gear type machining apparatus of the present invention may be incorporated into an extrusion screw as a part of a kneading part such as an injection molding machine, an injection blow molding machine, an inflation apparatus, or a T die. Further, the gear type machining apparatus of the present invention can be connected in a vertically stacked manner by combination with a mandrel. By vertically stacking, the installation area of the entire processing apparatus can be made smaller than that of a general screw extrusion kneader.

Unlike the gear type metering pump which is generally used, the gear type transfer unit used in the present invention focuses on the mixing effect rather than the metering. The gear shape of the gear-type transfer unit changes the center elasticity depending on the size of the tip R of the gear. The flow rate of the substance in the gear changes due to the angular difference between the tangent line of the gear groove and the center line. As the gear rotates, the material is cut and mixed in the gear groove. By roughening the gear and housing surface shape, the metering ability is reduced, but the center elasticity can be increased. It is the same as a general gear pump that the metering changes depending on the gear groove volume and the gear rotation speed.

It is also possible to install the gear-type transfer unit and the screw unit separately. In this case, the groove of the gear-type transfer unit gear can be vertically installed so as to be orthogonal to the screw shaft. Moreover, it is preferable that the gear-type transfer unit is incorporated as a module to facilitate compatibility. This is the same in the case of the horizontal type, and is the same module replacement method as that used in a general twin-screw extruder. This is because the viscosity varies depending on the substance used, and therefore, even if the gears and clearances are the same, the reverse flow resistance varies depending on the viscosity, and the desired pressure and the required shear strength can be easily selected. The modular system is also advantageous for cleaning the device.

Supercritical or subcritical gas chemistry includes, for example, chemical decomposition such as hydrolysis, alcoholysis, enzymatic decomposition, mixing of fine particles without surface treatment, mixing of liquid and polymer, mixing of insoluble polymer without using compatibilizer, etc. Examples include chemical actions such as mixing, solvent extraction, and steam extraction. The catalyst, auxiliary material, and the like may be appropriately quantitatively supplied from the raw material supply unit, or may be quantitatively supplied by a plunger pump, a gear pump, or the like halfway through a low-pressure gas supply unit or liquid injection. As the supercritical or subcritical gas, low molecular weight compounds such as carbon dioxide, methanol, acetone, nitrogen gas, and water may be used, and among them, carbon dioxide, which has mild conditions and is not explosive, is often used.

Examples of hydrolysis include, for example, starch, kenaf, bacus, cellulose, protein, fat and the like, which are decomposed into polysaccharides, oligosaccharides, monosaccharides, amino acids, alcohols and the like. As a catalyst, an acid is used as a saccharide, and an alkali or an enzyme such as amylase, peptidase, or lipase is used as a protein. The supercritical condition of carbon dioxide gas is 31 ° C. and 7 MPa. However, when an enzyme is used as a catalyst, it is preferable to operate in a temperature range in which the enzyme is not deactivated, for example, 35 to 40 ° C. and 7 MPa or more. When an acid or alkali is used as a catalyst, it is preferable to increase the temperature because reaction efficiency can be improved and productivity can be improved.

As an example of alcoholysis, for example, a so-called PET bottle can be collected, and the crushed flakes can be supplied to the chemical action device of the present invention by supplying flakes and methanol, and the polyethylene terephthalate can be alcoholized with methanol and recovered as terephthalic acid methyl ester. After rectification and removal of impurities, polyethylene terephthalate can be produced by polymerizing methyl terephthalate again. Further, ethylene diol can be used in place of methanol and recovered as bishydroxyethylene terephthalate to produce polyethylene terephthalate in the same manner. Increasing the temperature of alcoholysis is preferable because the reaction efficiency increases and productivity can be improved.

As an extraction example, for example, orange peel can be directly supplied to the processing apparatus of the present invention, and limonene can be extracted from the orange peel. Increasing the extraction temperature to near the boiling point of limonene is preferable because it increases the extraction efficiency and improves the productivity. The extracted crude limonene is rectified to improve purity and used.

As an example of mixing, for example, in order to improve the heat resistance of biodegradable polylactic acid, pellets can be produced by supplying inorganic fine particles as a crystallization nucleating agent to the processing apparatus of the present invention. By using the processing apparatus of the present invention, an inorganic fine particle crystallization nucleating agent is supplied in an aqueous dispersion, mixed under a carbon dioxide gas subcritical condition in a state of hydrolysis of polylactic acid to a low molecular weight, and then dehydrated and condensed. Since the dispersion is good, transparent polylactic acid pellets can be produced.

Examples of foaming include extrusion foaming and injection by injecting gas such as carbon dioxide and nitrogen gas, volatile substances such as butane and pentane from the decompression section, and mixing and feeding thermochemical foaming agents such as diazo compounds from the hopper. It can be incorporated into devices such as foam. As an example, FIG. 7 shows an example of a multi-stage gear type foam injection molding machine / extruder. In this case, it can be incorporated into a general plunger type injection molding machine.

In this example, the multi-stage gear extruder of the present invention shown in FIG. 6 was used. Since the screw corresponds to the raw material with a lot of moisture, a single screw with a length of 50 mm, a length of 350 mm, a biaxial paddle screw and a length of 400 mm are used at the bottom of the raw material supply hopper. The multi-stage gear used all three stages, and the multi-stage gear driven by the servo motor used all two stages. The dimensions of the gear main part are described below. The stage where only the dimension of the gear thickness of the A-axis and B-axis (hereinafter referred to as “tooth thickness”) is described, and the tooth thickness of the C-axis is not described is the structure described as the step-down part X or the step-up part Y. The stage where the tooth thickness of the C-axis is described is the structure shown as the kneading part Z. The pressure described next corresponds to the inlet side pressure described in the next stage as the outlet side pressure in the indicated stage, and the unit is (MPa).
The pitch circle diameter of all gears was 46 mm, and module 2 was adopted.
1st stage A-axis, B-axis tooth thickness 87mm 0.88 (measured value)
Second stage A-axis, B-axis tooth thickness 92mm 5.29 (design value)
3rd stage A-axis, B-axis tooth thickness 48mm / C-axis gear 20mm 8.82 (design value)
Servo motor drive / pressure control unit 1st stage A-axis, B-axis tooth thickness 20mm 8.8 (measured value)
Second stage A-axis, B-axis tooth thickness 28mm 4.41 (design value)
A device consisting of a die with a round hole nozzle, an underwater cutter and a dryer was used.

The following operating conditions were balanced at an extruder shaft speed of 80 rpm and a servo motor speed of 120 rpm. The temperature set by the heater is set to 160 ° C only under the inlet hopper, the temperature set to each part is set to 230 ° C, and the raw polylactic acid and 5 wt% mica water dispersion raw material ratio 1.0 blend are mixed at 30 kg / hour. Supplied. Carbon dioxide was reduced in pressure to 0.88 MPa from the gas inlet and injected. The pressure of the resin pressure gauge in the pressure adjustment unit by the servo motor is supercritical at 8.8 MPa, and the residence time to reach the pressure adjustment unit gear is about 20 seconds (calculated value). The water pump reduced compression polymerization at the reduced pressure vent, and the molecular weight of polylactic acid was recovered. It was clear that the obtained pellets were transparent and dispersibility reached the nano level despite containing inorganic fine particles.

In this example, the same multistage gear extruder as shown in FIG. 6 was used.

The following operating conditions were balanced at an extruder shaft speed of 80 rpm and a servo motor speed of 120 rpm. The temperature set by the heater is set to 160 ° C only under the inlet hopper, the temperature set for each part is set to 190 ° C, and blended 89.3 wt% of the raw polylactic acid and 10.7 wt% of the starch aqueous dispersion (solid content 50 wt%). And supplied at 30 kg / hour. Carbon dioxide was reduced in pressure to 0.88 MPa from the gas inlet and injected. The indicator pressure of the resin pressure gauge in the pressure adjustment unit by the servo motor is 8.8 MPa carbon dioxide supercritical, and the residence time to reach the pressure adjustment unit gear is about 26 seconds (calculated value). The water pump reduced compression polymerization at the reduced pressure vent, and the molecular weight of polylactic acid was recovered. It was clear that the resulting pellets were clear and dispersible to the nano level despite containing starch.

In this example, the multistage gear type foam injection molding / extruder shown in FIG. 7 was used with the number of multistage gears changed to 10 stages. A single screw flat screw having a diameter of 50 mm and a length of 750 mm at the lower part of the raw material supply was used. Describe the dimensions of the main part. Only the tooth thicknesses of the A-axis and B-axis are described, and the stage where the C-axis tooth thickness is not described is the structure described as the pressure-lowering part X or the pressure-boosting part Y, and the stage where the tooth thickness of the C-axis is described is kneaded. This is the structure shown as part Z. The pressure described next corresponds to the inlet side described in the next stage in the outlet side pressure described in the stage, and the unit is (MPa).
The pitch circle diameter of all gears was 46 mm, and module 2 was adopted.
1st stage A-axis, B-axis tooth thickness 12mm 0.74 (measured value)
Second stage A-axis, B-axis tooth thickness 92mm 5.19 (design value)
Third stage A-axis, B-axis tooth thickness 44mm / C-axis tooth thickness 18mm 9.8 (design value)
4th stage A-axis, B-axis tooth thickness 36mm / C-axis tooth thickness 18mm 9.8 (design value)
5th stage A-axis, B-axis tooth thickness 18mm 9.8 (design value)
6th stage A-axis, B-axis tooth thickness 36mm / C-axis tooth thickness 18mm 9.8 (measured value)
7th stage A-axis, B-axis tooth thickness 18mm 5.88 (design value)
8th stage A-axis, B-axis tooth thickness 22mm 2.94 (design value)
9th stage A-axis, B-axis tooth thickness 32mm 0.2 (design value)
10th stage A-axis, B-axis tooth thickness 312mm
A water-cooled round die having an effective total length of 1200 mm was attached to the rear of the tenth stage of the multi-stage gear group. The inner diameter of the outer water-cooled round die is 80 mm outlet diameter, the core water-cooled round die adopts a tapered taper, and the outer diameter is 60 mm outlet diameter.

The heater temperature was set to 160 ° C., the shaft rotational speed was 80 rpm, 99.5% by weight of the main raw polyethylene and 0.5% by weight of wax were dry blended and charged from the hopper. Compressed air from the compressor was reduced to 0.74 (MPa) by a pressure reducing valve and injected into the gas inlet. As a result, a cylindrical continuous foam having an outer diameter of 80 mm and an inner diameter of 60 mm was obtained. The foam cell was small, the foam ratio was about 50 times, and the time-equivalent discharge amount was 35 kg.

In this example, the multi-stage gear type foam injection molding / extruder shown in FIG. However, the round die of the apparatus of Example 3 was removed, and a mechanical nozzle for an injection molding machine was attached and used. For a simple prototype test, aluminum was used for the mold, 6 mm diameter holes for material leakage were provided at 8 locations, and the structure was configured to press contact with the mechanical nozzle with hooks. In addition, a drain was provided between the mechanical nozzle and the mold, and a switching valve between the direction of flowing in the mold and the direction of flowing out of the drain was attached. The gas inlet was connected to a carbon dioxide gas cylinder with a pressure reducing valve reduced to 0.74 (MPa).

Dry blend of 99% by weight of the raw polylactic acid and 1% by weight of trimellitic anhydride is supplied at a rate of 35 kg / hour from the hopper, 0.74 MPa of carbon dioxide gas is supplied from the carbon dioxide gas inlet, and the temperature is 230 ° C. The sixth stage rear kneaded continuously under supercritical carbon dioxide conditions of 9.8MPa, and by switching temporarily from the drain side to the mold side with the switching valve, the foamed polylactic acid is injected into the room temperature tro box mold Thereafter, the mold was water cooled. The Toro box of foamed polylactic acid foamed about 50 times, produced fine foam nuclei, and was able to mold a Toro box without flash marks.

Claims (8)

The material gas are mixed, as fluid from the upstream side sequentially while transported to the downstream side kneaded compressed, containing a supercritical state or gas subcritical state, a processing device for processing, transport unit Two or more gear-type transfer units with different capacities are provided, and the pressure for compressing the gas contained in the fluid is controlled by the difference between two successive gear-type transfer units, or part of the transfer fluid is backflowed and substantially transferred In addition to being configured to have a constant capacity, a gas injection port is provided between two continuous gear-type transfer units in the two or more gear-type transfer units, and an upstream side of the gas injection port is provided. transfer unit capacity by stage gear at Oh Rukoto at less than the transfer unit capacity due to the gear of the downstream stage of the gas inlet, between the gear transfer unit of two stages wherein consecutive for stepping down the gas a step-down unit of the formation, the gas injected from the gas inlet Multistage gear machining apparatus characterized capable to be configured.   The multi-stage gear type machining apparatus according to claim 1, wherein a plurality of gears paired with the two-stage gear type transfer part having different continuous transfer part capacities are provided.   3. The multi-stage gear type machining apparatus according to claim 1, wherein the gear type transfer unit is provided following the extrusion screw. The multistage gear type machining apparatus according to any one of claims 1 to 3 , wherein the gear type transfer unit generates a pressure sufficient to form a supercritical or subcritical state. The multistage gear type machining apparatus according to any one of claims 1 to 4 , which is used for gas foam molding. Using a multi-stage gear machining apparatus of any one of claims 1 to 4, the processing method of performing kneading, decomposition, extraction or chemical synthesis. Gears respectively attached to the A axis, the B axis, and the C axis adjacent to the A axis, which are parallel to each other With
The gear-type transfer unit is configured by two gears of the A-axis and the B-axis, and the fluid Part of the gear passes through the outer periphery of the A-axis gear from the downstream side of the gear-type transfer section and enters the C-axis gear. The gear-type transfer unit is supplied to the mouth and returns from the outlet of the C-axis gear to the outer periphery of the A-axis gear. It is configured to flow backward to the upstream side of the motor and be transferred again to the gear-type transfer unit. The multistage gear type machining apparatus according to any one of claims 1 to 5. Attached to the D-axis parallel to the A-axis, B-axis and C-axis and next to the B-axis And a part of the fluid is fed from the downstream side of the gear-type transfer unit to the B-axis teeth. After being supplied to the D-axis gear inlet through the outer periphery of the vehicle, the D-axis gear outlet Return to the outer periphery of the B-axis gear and back flow upstream of the gear-type transfer unit, and then transfer again to the gear-type transfer unit. The multi-stage gear type machining apparatus according to claim 7, wherein the multi-stage gear type machining apparatus is configured to be fed.

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